System of signaling for mine-hoists.



M. A. WHITING. SYSTEM OF SIGNALING FOR MINE HOISTS. APPLICATION FILED JULY 21,1916.

Inventor: max film Mixing, WW

His fi ctar-ney.

UNIT D STATES PATENT oEEICE.

MAX A. WHI'I'ING, 0F SCHENEGTADY, NEW YORK, .AS-SIGNOR T0 GENERAL ELECTRIC COMPANY, A con'ronArIoN or NEW YORK.

SYSTEM OF SIGNALING FOR MINE-HOISTS.

To all whom it may concern: 7

Be it known that I, MAX A. WHITING, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Systems of Signaling for Mine-Hoists, of which the following is a specification.

This invention relates to a system of signaling for mine hoists, and its object is to prevent the overwinding of the cages when men are being lifted.

In the operation of vertical shaft mine hoists, particularly in coal mines operating at a moderate depth, it is common practice to hoist and lower men on the main hoist used for handling the ore or coal. In some States the law requires that men he hoisted or lowered only Fin balance that is, with the other drum clutched in so that the cage and rope on the other side help to balance the cage and rope on the side on which the men are being handled. In metal mines it is common practice to use a selfdumping skip for the ore and a separate cage for the men, said cage being hung directly above or below the skip; In coal mines, it is com- 'mon practice to use a self-dumping platform cage on which cars of coal, slate, etc., are carried, the cars being locked on the platform and dumped by horns which tilt the platform at the top of the head frame or breaker. Men are hoisted or lowered on these same platforms after the cars are removed.

In either of these cases, it is necessary, when hoisting men, to stop the cage at the surface, commonly called the collar, but when hoisting ore or coal it is necessary to lift the cage into the dump, some distance higher.

Even overwind protective devices are used to protect against running either cage or skip into the head sheave, there may be a considerable element of danger in hoisting men, particularly with a self-dumping platform, the tilting of which in the dump is almost sure to' dump the men down the coal chute. Accidents of this kind halve happened in two ways, first by failure to stop in time when hoisting a trip of men, and secondly, after caging' on a trip of men at the collar, by starting the hoist in the wrong direction andtaki'ngthe men up into the dump. It is the object of my invention to Specification of Letters Patent.

Patented Oct. 9, 1917.

Application filed July 21, 1916. Serial No. 110,609.

provide means of protection against such accidents, without interfering with the normal use of the hoist. I likewise avoid the possibility of any confusion which would require telephoning between the hoist platform and the collar or between the hoist platform and the foot or any one of the mine levels to which men are being lowered or from which they are being raised when cutting the man hoisting overwind devices in or out.

The law in many States forbids handling men simultaneously on both sides. At times, on a balanced hoist, the men will be handled entirely on one side, so that the man overwind device for that side can be cut in and left during several trips. But when the movement of men is principally in one direction, 2'. c. all going in or all coming out, time can usually be saved by handling men alternately on both sides. For example, after unloading a trip of men at the collar, thecage just unloaded will be hoisted into the dump in order to bring the other cage to the foot to take on another trip of men. The man overwind devices on the two sides should preferably, therefore, be capable of being cut in or out on either side without delay or confusion.

In hoisting ore or coal it is common practice for the cage tender to give the hoist operator one bell to hoist, it being unnecessary for the hoist operator to reply before beginning to hoist. But when handling men, it is a common rule, required by law in some States, for the cage tender at the foot or any one of the mine levels, or at the collar, as the case may be, to give theoperator a preliminary signal, usually three bells, to which the operator must reply, usually with one bell, to show that the cage is standing ready to take on a trip of men. When the men are on the cage and in the clear, the hoist operator is given another signal, usually one bell, to start the hoist. Where such a code of signals is in use, under all normal conditions the code is rigidly adhered to in handling men. My invention provides means whereby the hoist operator cannot signal his reply to a signal for hoisting men unless he first throws the man overwind device, which may be a limit switch, into circuit. In order to accomplish this result with the smallest practicable number of wires down the shaft, I prefer the system shown in the accompanying drawing which is a diagram of circuits and apparatus, embodying my invention,

A balanced hoist is shown, having two cages 1 and 2, operated by the hoisting motor 3. The hoisting motor 3 may be any suitable motor, that shown upon the draw ings being a three phase induction motor receiving current from the three phase source of supply S. The customary electromagnetically actuated reversing switches RS are adapted to reverse the direction of rotation of the motor to raise or lowerthe cages 1 and 2 as may be desired. A master controller C is adapted to complete the circuit through the proper electromagnet of the reversing switch RS for energizing the motor to operate in the direction desired. The speed of the motor may be controlled in the usual manner by varying the resistance R in the rotor circuit. The reversing switches RS, the master controller C and certain parts of the signaling system to be hereinafter more fully described, are conveniently placed on the hoist platform near the hoisting motor and drum. For the sake of simplicity the hoist platform has been omitted from the drawings.

Limiting devices such as switches 4 and 5 control the motor under certain conditions to be hereinafter more fully described. The limiting devices are operated responsively to the movement of the cages by any suitable moving part of the hoisting apparatus, in the particular embodiment of my invention shown the switches 4 and 5 are brought into service by some means such as lugs on the hoisting cables from which the cages 1 and 2 are suspended when said cages are lifted beyond the danger point at the collar 6. Current for the signaling system is conveniently taken from supply mains 7 and 8 which receive current from the low potential side of a potential transformer P, the high potential side of which receives current from one of the phases of the three phase supply circuit S.

A suitable switch, such as the springopened push button 9 is located at the foot of the shaft, and when closed causes a bell 10 to ring at the foot and another bell 11 to ring at the hoist platform. In order to get the reply signal above referred to, the cage tender at the foot must shift a double throw switch 12. An interlocking device 13,, cooperating with the cage 1 prevents him from moving this switch to the right and compels him to move it to the left, thereby closing a circuit from the main 7 to the branch condu'ctor 14. Before the hoist operator can send the reply signal he must move a double throw switch 15 to the left carrying the segment 16 into contact with the finger 17 18, and making it possible for the hoist operator to close the circuit of the bells 10 and 11 byv means of the lower contact disk on the double push button 19.

If cage 2 had been at the foot the cage tender there would have been obliged to shift the switch 12 to the right on account of the engagement of the cage with the ri ht hand end of the interlocking device. T is would have closed the circuit through branch conductor 20, and the hoist operator would have been compelled to throw the switch 15 to the right, thereby closing the contact plate 21'on the fingers 17 22 before he could send a reply signal to the cage tender by means of the upper contact disk on the push button 19.

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The switch 15 is shown in its central or neutral position. When moved to the right or the left from'this position, the circuit 23 or 24: is opened so that the respective limit switch is placed in control of the motor and if the cage runs up beyond the danger point at the collar 6 the motor will be stopped. When hoisting ore or coal, the switch 15 is left in the central position, so that neither limit switch will operate when the cage passes up beyond the collar no reply signal by custom being required when the cage tender at the foot signals to hoist into the dump.

The signaling circuits are duplicated for the cage tender at the collar, so that if he wishes to signal the hoist operator to lower a cage he has merely to close the spring-opened push button 27, which will ring the bell 28 at the hoist platform. If a trip of men is to be lowered the cage tender at the collar will throw the double throw switch 29 in the only direction in which the interlocking device 30 will permit it to be moved, and thereby make it possible for the hoist operator to close the circuit of the signal bell 31 with the push button 32, after throwing the switch 15 to the proper position.

It is evident that the hoist operator cannot accidentally hoist the men into the dump, be-

cause the shifting of the switch 15 to enable him to give a reply signal to the operator at the collar will open the short circuit 23 or 24 and thus cause the limit switch to sto the motor if the cage is started toward the dump. The dump has not been shown on the drawings, but it is to be understood that it is located a suitable distance above the collar 6.

When it is desired to handle men entirely on one side for several trips, it is evidentl unnecessary for the hoist operator to shi the switch 15 between trips. 7

When it is desired to handle the men suecessively on both sides, to save time when bringing men out where there are none waiting to go in, the procedure is as follows: Men are caged at the foot, and after the cage is stopped at the collar and the men are off, the man at the collar gives the hoist operator the signal to hoist this empty cage into the dump. The hoist operator need not reply to this signal, but he throws the switch 15 to the middle position so as to cut the limit switches out of action before trying to hoist the empty cage up into the dump. Having hoisted it and thereby brought the other cage to the foot, the caging and hoisting of men in this latter cage will proceed in the usual manner.

The limit switches 4, 5 will be arranged and connected so as to open all control circuits necessary for cutting off power from the hoist motor by deenergizing the reversing switches RS, at the same time denergizing the hoist brake B, making an emergency application of the brake.

hat I claim as new and desire to secure by Letters Patent of the United States, is:

1. A signaling system for mine hoists, comprising a limit switch or switches for the hoist motor, a signaling circuit between the hoist platform and a distant station on the shaft, and a switch at the hoist platform which must be thrown in order to permit a reply signal to be sent, and when so thrown renders operative the appropriate limit switch.

2. A signaling system for mine hoists, comprising a limit switch or switches for the hoist motor, a double throw switch at the hoist platform controlling said limit switches, two signaling circuits controlled by said switch, and a double throw switch at a distant station on the shaft also controlling said signaling circuits.

3. A signaling system for mine hoists, comprising a limit switch or switches for the hoist motor, a double throw switch at the hoist platform controlling said limit switches, two signaling circuits controlled by said switch, a double throw switch at a distant station on the shaft also controlling said signaling circuits, and a push button at the hoist platform controlling both of said signaling circuits.

4. A signaling system for mine hoists, comprising a limit switch or switches for the hoist motor, a double throw switch at the hoist platform controlling said limit switches, a signaling circuit from a distant station on the shaft to the hoist platform, a reply signaling circuit having two branches, each controlled by its respective contact on the double throw switch, a double throw switch at the distant station also controlling said two branches, and a hand switch at the hoist platform for closing said branches.

5. A signaling system for mine hoists, comprising a limit switch or switches for the hoist motor, a double throw switch at the hoist platform controlling said limit switches, a signaling circuit from a distant station on the shaft to the hoist platform, a reply signaling circuit having two branches, each controlled by its respective contact on said double throw switch, a double throw switch at the distant station also controlling said two branches, a device interlocking with the cage at said station to prevent said last named switch from being thrown in the wrong direction, and a hand switch at the hoist platform for closing said branches.

In witness whereof, I have hereunto set my hand this 20th day of July 1916.

MAX A. VVHITING.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0. 

